In an Internet Protocol version 6 (IPv6) network, typically multicast is used for neighbor discovery. For example, Internet Engineering Task Force (IETF) Request for Comments (RFC) 4861 specifies how such neighbor discovery is performed. Yet, Internet of Things (IoT) devices often operate in a Low-power Wireless Personal Area Network (LoWPAN), where the links are often lossy, low-power, low-bit-rate, and/or short-range, thus multicast may not work well for device discovery in a LoWPAN environment for IoT devices.
Software-defined networking (SDN) is a network architecture that aims at decoupling control plane functions from data plane functions such that separate apparatuses may be utilized for different functions. In the SDN architecture, network intelligence and states are logically centralized, and the underlying network infrastructure is abstracted from the applications. As a result, networking may be simplified and new applications become feasible. For example, network virtualization can be accomplished by implementing it in a software application where the control plane is separated from the data plane. Also, a network administrator of a SDN system may have programmable central control of network traffic without requiring physical access to the system's hardware devices. With these benefits, SDN architecture based systems (referred to as SDN systems or SDN networks exchangeably herein below) are gaining popularity among carriers and enterprises.
A SDN system includes one or more SDN controllers and a set of network elements managed by the SDN controllers. It is challenging to manage a LoWPAN in a SDN architecture, so that the one or more SDN controllers may, at a central location, perform access control of remote LoWPAN nodes and discover the LoWPAN nodes as they join/leave.